Patent GB-809211-A (GB)
Title: Improvements in or relating to teleprinter transmitters
IPC: H04L17/06
Filed: 1957-03-04
Abstract: 809,211. Printing-telegraph transmitters. SIEMENS & HALSKE A.G. March 4, 1957 [March 3, 1956], No. 7151/57. Class 40 (3). [Also in Group XXXVII] In a teleprinter transmitter operated by a keyboard or a perforated tape, the switch means for controlling the transmitter contacts is actuated by an intermediate member urged by a spring into contact with an eccentric or a motor-driven shaft, which performs one or more revolutions during the transmission of each code element, and the switch is controlled in accordance with the nature of the individual code elements by a single mobile switch element controlled by a single operating member connected therewith and co-operating by contact with sensing means which are arranged to explore sequentially the individual positions of selector members which are set by the operation of the keyboard or of the perforated tape. As shown in Fig. 1, the selective positioning of bars 11 ... 15 by a keyboard or in response to a perforated tape is sensed by five U-shaped feelers 16 ... 20 having their shorter arms in engagement with equally spaced cams 21 ... 25 on a shaft 28 driven by a clutch 30 from gearing 2, and their longer arms associated with the ends of the bars 11 ... 15. These longer ends of the feelers 16 ... 20 engage a wire 7 carrying an operating block 6 carried on a resilient member 5 actuated downwardly by a cam 4 which completes a revolution during the period of each signal element. According to the position of the block 6, the movement of the member 5 actuates one of the arms 8, 9 of V- shaped switch springs having their other arms 8<SP>1</SP>, 9<SP>1</SP> operatively associated with projections a, b of a member connected by a shaft S to a switch-operating member sw. A sixth feeler 27 is operated by its cam 26 to provide the stop element and the wire 7 then remains in its unoperated position to provide the start element. The shaft 3 carrying the cam 4 may be in continuous rotation, and for keyboard operation the clutch 30 is operated when the shaft 3 is in a predetermined position. In a modification, Fig. 5, the wire 7 carrying the block 6 is actuated by the arm 52a of an L-shaped member 52 pivoted at 53 and normally held in the position shown against a stop 59 by springs 54, 55. For the transmission of a signal the engagement of the arm 52b of the member 52 by the downward movement of a member 58 rocks the arm 52a against a shaped cam sleeve 51 having grooves 51g cut so that over one half of the circumference of a groove the arm 52a can move inwardly, i.e. to the left, and rock the wire 7 unless it is blocked by the grooved end of the associated one of the selector members 11a ... 15a set by the keyboard or tape transmitter, or the end of the fixed member 50 controlling the transmission of the start element. The remaining circumferential portion of each groove is of spiral form and engages the arm 52a, whether or not it has been engaged by an end of a selector member 11a ... 15a to move it into operational relation with respect to the subsequent selector member. After the setting of the fifth bar 15a has been sensed, the arm 52a moves inwardly to rock the rod 7 and block 6 to effect the transmission to the stop element of the code combination, subsequent to which the return, i.e. upward, movement of the member 58 allows the arm 52a to move under the action of the springs 54, 55 to its initial position in relation to the guide block 59. In a further modification, Fig. 8 (not shown), the wire 7 is operated by one arm of a V-shaped member traversed by means of a second arm engaging a cam sleeve across the ends of five resilient fingers selectively raised in accordance with the signal elements of the code combination to be transmitted. The arm engaging the ends of the fingers is also under the control of a set of cams which are all similar and have high and low portions extending over half the circumference. The arm operating the wire 7 is normally held out of engagement with its cam sleeve and is released for operation by a pivoted blade which is raised for the transmission of a signal. The V-shaped member is carried by a spring-biased rotatable hub member and its arms engage projections of the forked arms of a restoring frame which is rotated against a spring during the period of the transmission of a signal and operates after the end of the stop element to restore the V-shaped member to its initial position. Construction and operation of signal transmitting switch, Fig. 4. The contacts 34, 35 are operated by extensions 33a, 33b of an operating member 33 pivoted at 32 and carrying projections 33c, 33d engaged by the arms 40g, 41g of similar switch springs 40, 41 pivoted on studs 42, 43. The arm 41b of the spring 41 rests on a fixed stop 31b and the arm 41g has an extension 41a engaged by one leg of a bent spring 44 having its other leg in engagement with a projection 39a of a pivoted detent 39 having an extension 39b resting on a latching projection 33e of the member 33 which is held in the position shown by the latching projection of the detent 38. With the operating block 6 in the position shown, the upward movement of lever 5 by the eccentric cam 4 engages the end 40b of the spring 40 which is rocked so that the arm 40g engages the projection 33c and rotates the member 33 to open contacts 34 and to allow contacts 35 to close. Also, the end 38b of the detent 38 is raised above the latching projection 33e behind which the latching projection 39b falls to hold the member 33 in its operated position.